Large Eddy Simulation of the PRECCINSTA burner

For the first time the Reaction-Diffusion Manifold (REDIM) technique is implemented together with a presumed Filtered Density Function (FDF) to carry out Large Eddy Simulation (LES) of lean premixed swirling flames in the well-known PRECCINSTA burner. The REDIM approach reduces detailed chemical kinetics based on low-dimensional reaction-diffusion manifolds in composition space, so that many species can be accurately estimated at a relatively low computational cost via a look-up table. In the present work, only one reduced coordinate, the CO2 mass fraction, is considered in the REDIM look-up table. Implementation of the REDIM/FDF model is performed with two presumed FDF shapes, top-hat and clipped Gaussian. Two premixed flames are simulated, with equivalence ratios 0.75 and 0.83, respectively. Velocity, temperature and species concentration profiles are discussed and compared to the experimental data. The results are in good overall agreement with the corresponding experiment. It is also shown that the LES results obtained with the two presumed FDFs are very similar and the reason for this is analysed.